Abstract: The invention relates to a device and a method for the aftertreatment of exhaust gases from combustion engines, in particular from internal combustion engines. The device according to the invention and the method are intended to be of simple construction, should be inexpensive to produce and operate and should have less adverse effect on the flow conditions in the exhaust gas stream. To achieve this object, at least one region which is filled with beads is provided in the exhaust-gas stream, the beads preferably being hollow beads. The exhaust gas from the combustion engine is passed through this region, and it is possible to achieve particle agglomeration with simultaneous separation of these particles. In addition, further regions which are filled with metal fibers may follow the at least one region filled with beads, and the exhaust gas is additionally passed through these further regions.

Abstract: An emission abatement assembly includes one or more DPNR devices for removing both NOX and particulate soot from the exhaust gas of an internal combustion engine. Reformate gas from a fuel reformer is used to selectively regenerate the DPNR device or devices. A method of operating an emission abatement assembly is also disclosed.

Abstract: An exhaust gas purifying catalyst including a catalyst component containing a refractory inorganic oxide carrying a platinum family metal, a nitrogen oxide adsorbent, and a hydrocarbon adsorbent and a catalyst component for the purification of nitrogen oxide and a method for the purification of an exhaust gas by the use of the catalyst.

Abstract: An exhaust gas purifying catalyst comprises a catalytic ingredient including rhodium, at least one of platinum and palladium, at least one of absorption materials for absorbing NOx, a porous carrier, and a monolithic support for supporting the catalytic ingredient. The exhaust gas purifying catalyst includes a plurality of catalytic layers containing at least a part of the catalytic ingredient, and rhodium is contained at least in an outermost layer of the catalytic layers. A rhodium amount in the catalytic ingredient is 0.5 g or more for each liter of the catalyst, and a rhodium amount contained in the outermost layer accounts for 80 wt % or more of a total rhodium amount. A weight of the catalytic layer at the outermost layer is 40 wt % or below of a total weight of the catalytic layers.

Abstract: A system and method for the control of emissions from a diesel engine exhaust, comprises a catalyst (14) to convert NO to NO2, a filter (16) to trap soot and hold it for combustion with the NO2, and a NOx absorber (28), with means to regenerate the NOx absorber by injecting reductant or other reactant (injector 18) upstream of the absorber, and at least during regeneration, passing the exhaust gases leaving the absorber through a three-way catalyst (30).

Abstract: A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.

Abstract: A process for heating a carbon filter in an exhaust gas system of an internal combustion engine, in particular a diesel engine, with at least one catalytic converter and a carbon filter mounted downstream from the catalytic converter in the direction of flow for accumulating carbon. The catalytic converter mounted upstream from the carbon filter is heated to the extent that the amount of heat from the catalytic converter introduced into the carbon filter heats the carbon filter to the extent that combustion of the carbon is initiated.

Abstract: A NOx reduction method includes treating a first gas containing NOx, producing a second gas containing NO2, reducing a portion of the NO2 in the second gas to N2, and producing a third gas containing less NOx than the first gas, substantially all of the third gas NOx being NO. The method also includes treating the third gas, producing a fourth gas containing NO2, reducing a portion of the NO2 in the fourth gas to N2, and producing a fifth gas containing less NOx than the third gas, substantially all of the fifth gas NOx being NO. Treating the first and/or third gas can include treatment with a plasma. Reducing a portion of the NO2 in the second and/or fourth gas can include reducing with a catalyst. The method can further include controlling energy consumption of the plasmas independent of each other.

Abstract: A process for treating exhaust gas from internal combustion engines wherein the combustion exhaust gas contains HC, CO, O2, soot and possibly NOx. In treating the combustion exhaust gas, HC is oxidized to COx and H2O: NO, if present, is oxidized to NO2 and soot is oxidized by reaction with NOx. In addition, NOx is generated by oxidizing ammonia and NOx is introduced into the exhaust gas upstream of the oxidization of soot by reaction with NOx.

Abstract: A high-surface-area (greater than 600 m2/g), large-pore (pore size diameter greater than 6.5 angstroms), basic zeolite having a structure such as an alkali metal cation-exchanged Y-zeolite is employed to convert NOx contained in an oxygen-rich engine exhaust to N2 and O2. Preferably, the invention relates to a two-stage method and apparatus for NOx reduction in an oxygen-rich engine exhaust such as diesel engine exhaust that includes a plasma oxidative stage and a selective reduction stage. The first stage employs a non-thermal plasma treatment of NOx gases in an oxygen-rich exhaust and is intended to convert NO to NO2 in the presence of O2 and added hydrocarbons. The second stage employs a lean-NOx catalyst including the basic zeolite at relatively low temperatures to convert such NO2 to environmentally benign gases that include N2, CO2, and H2O.

Abstract: A canister (1) contains a catalyst for generating NO2 and a filter (8) for trapping PM, e.g. from diesel engines. The filter is thermally isolated from the canister, and preferably is surrounded by an annular monolith comprising the NO oxidation catalyst or a SCR catalyst. The invention facilitates the combustion of PM even at low exhaust gas temperatures, in a compact device.

Abstract: An adsorbent for a hydrocarbon, comprising a calcined &bgr;-type zeolite showing a powder X-ray diffraction such that the sum of X-ray diffraction intensities at lattice spacings d=1.15±0.03 nm and d=0.397±0.01 nm, is at least 90% of the diffraction intensity at d=0.346±0.01 nm of Catalysis Society reference catalyst JRC-Z-HM-20(3).

Abstract: A new method for design and scale-up of photocatalytic and thermocatalytic processes is disclosed. The method is based on optimizing photoprocess energetics by decoupling of the process energy efficiency from the DRE for target contaminants. The technique is applicable to photo-thermocatalytic reactor design and scale-up. At low irradiance levels, the method is based on the implementation of low pressure drop biopolymeric and synthetic polymeric support for titanium dioxide and other band-gap media. At high irradiance levels, the method utilizes multifunctional metal oxide aerogels and other media within a novel rotating fluidized particle bed reactor.

Abstract: The invention relates to a process for the treatment of gases with high oxygen content, with a view to controlling nitrogen oxide emissions, characterized in that use is made of a catalytic composition comprising manganese oxide and at least one oxide chosen from cerium oxide and zirconium oxide. This composition may furthermore comprise at least one other element chosen from those in groups VIII, IB, IVB and VB. The process of the invention applies in particular to the treatment of exhaust gases of internal-combustion engines, more particularly diesel engines or lean-burn engines.

Abstract: An exhaust gas treatment apparatus and method for its use includes an upstream catalyst and a downstream catalyst. The upstream catalyst contains a catalytic metal effective at least for the oxidation of hydrocarbons in the exhaust gas stream, and preferably contains a palladium catalytic component and contains substantially no oxygen storage components, i.e., oxides of cerium, cobalt, iron, magnesium, molybdenum, nickel, praseodymium, tungsten and vanadium, but the downstream catalyst includes an oxygen storage component. Preferably, the upstream catalyst is a close-coupled catalyst. The downstream catalyst may be an underfloor catalyst or a close-coupled catalyst, in which case there is, preferably, an additional, underfloor catalyst.

Abstract: A method of treating exhaust from an internal combustion engine having an emission reduction device, such as a lean NOx trap. Exhaust from the engine is directed to a first sulfur trap, which treats the exhaust and discharges exhaust that is substantially free of sulfur. The exhaust from the first sulfur trap is normally directed to the emission reduction device, but is diverted to a second sulfur trap when the first sulfur trap is saturated. During this diversion, a reducing agent introduced upstream of the first sulfur trap aids in purging the first sulfur trap and in reducing metal sulfates and metal sulfites in the first sulfur trap to hydrogen sulfides, which are then treated by the second sulfur trap. When the first sulfur trap is thus purged, the exhaust gas is again directed to the emission reduction device.

Abstract: A method for reduction of NOx in a lean gaseous stream includes passing the gaseous stream at a temperature within the NOx sorbing temperature range through a catalyzed trap member having an oxidation catalyst intimately combined with a sorbent material. The sorbed NOx is periodically removed by introducing a combustible component into the gaseous stream and oxidizing it on the trap member to thermally desorb the NOx. The amount of combustible component introduced is limited to maintain the gaseous stream bulk composition lean and to avoid increasing the bulk temperature of the gaseous stream to a temperature which is too high for effective lean NOx abatement treatment. A suitable NOx abatement catalyst is used to reduce the desorbed NOx. Sorbing (trapping) and desorbing periods are alternated, usually in response to the temperature of the gaseous stream, and an apparatus to carry out the process is provided.

Abstract: The invention is especially directed to a system for purifying exhaust gases of diesel or gasoline engines containing on average an excess of oxygen, this system including three operational units being an oxidation catalyst (3), a particle separator (4), and an NOx adsorption catalyst (5), this system reducing the amount of hydrocarbons, carbon monoxide, nitrogen oxides and particles present in exhaust gas. The invention is also directed to methods for purifying exhaust gases.

Abstract: A multi-zoned catalytic trap for conversion of NOx in an exhaust gas stream which emanates from an engine which is operated with periodic alternations between lean, and stoichiometric or rich, conditions. The catalytic trap comprises a first zone, a second zone and, optionally, one or more intermediate zones disposed between the first zone and the second zone. Each of the zones comprises a catalytic trap material coated on a refractory carrier member. In the first zone, the catalytic trap material comprises a refractory metal oxide support having dispersed thereon a palladium catalytic component in the amount of about 30 to about 300 g/ft3, a platinum catalytic component in the amount of 0 to about 100 g/ft3 and a rhodium catalytic component in the amount of 0 to about 10 g/ft3; and a NOx sorbent comprising one or more basic oxygenated compounds of one or more alkaline earth metals and optionally, one or more basic oxygenated compounds of one or more alkali metals.

Abstract: A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.

Abstract: A process for removal of carbon monoxide, hydrocarbons, and nitrogen oxides from the exhaust gas from lean-burn, diesel and other engines which produce exhaust gases containing excess oxygen is disclosed. An exhaust gas from an engine operating at an air-fuel ratio above about 18 is contacted with a multi-component catalyst having at least two catalytic components, each capable of reducing nitrogen oxides within a range of exhaust gas temperatures that is different from the range of exhaust gas temperatures within which each other component is capable of reducing nitrogen oxides. Oxidation of the remaining reducing gases is also accomplished. One example of a two catalytic component catalyst of this invention has a first component of Au supported on alumina, which reduces nitrogen oxides at exhaust gas temperatures between about 600° C. and 900° C., and a second component of Pt supported on Y-zeolite, which reduces nitrogen oxides at exhaust gas temperatures below 600° C.

Abstract: A new method for design and scale-up of photocatalytic and thermocatalytic processes is disclosed. The method is based on optimizing photoprocess energetics by decoupling of the process energy efficiency from the DRE for target contaminants. The technique is applicable to photo-thermocatalytic reactor design and scale-up. At low irradiance levels, the method is based on the implementation of low pressure drop biopolymeric and synthetic polymeric support for titanium dioxide and other band-gap media. At high irradiance levels, the method utilizes multifunctional metal oxide aerogels and other media within a novel rotating fluidized particle bed reactor.

Abstract: A new method for design and scale-up of thermocatalytic processes is disclosed. The method is based on optimizing process energetics by decoupling of the process energetics from the DRE for target contaminants. The technique is applicable to high temperature thermocatalytic reactor design and scale-up. The method is based on the implementation of polymeric and other low-pressure drop support for thermocatalytic media as well as the multifunctional catalytic media in conjunction with a novel rotating fluidized particle bed reactor.

Abstract: A removal method of malodorous substance and deodorization device thereof enables un-treated gas containing soluble or insoluble malodorous substance contained complexly to be removed by only one treatment process as far as the degree of sensing nothing by organoleptic test. The un-treated gas containing soluble or insoluble malodorous substance contained complexly is flushed in compliance with necessity to remove insoluble malodorous substance, before converting insoluble malodorous substance into soluble substance by virtue of conversion catalyst to flush to be removed.

Abstract: A composition for abatement of airborne pollution by volatile organic compounds (“VOCs”) has an upstream composition which contains a protective adsorbent, e.g., Y zeolite, which is effective for adsorbing large VOC molecules, e.g., toluene, and a protective oxidation catalyst intimately intermingled therewith. The downstream composition contains a second adsorbent, e.g., a silver-containing ZSM-5, which is effective for adsorbing relatively smaller VOC molecules, e.g., propylene, and a second oxidation catalyst intimately intermingled therewith. Oxidation of VOCs while they are still retained on the adsorbents is promoted at temperatures lower than would be required if the VOCs were desorbed into the gaseous phase. Apparatus is provided including a first contact member (24) coated with the upstream composition and positioned upstream of a second contact member (32) coated with the downstream composition.

Abstract: A new method for design and scale-up of photocatalytic and thermocatalytic processes is disclosed. The method is based on optimizing photoprocess energetics by decoupling of the process energy efficiency from the DRE for target contaminants. The technique is applicable to both low- and high-flux photoreactor design and scale-up. The low-flux method is based on the implementation of natural biopolymeric and other low-pressure drop media support for titanium dioxide and other band-gap photocatalysts. The high-flux method is based on the implementation of multifunctional metal oxide aerogels and other media in conjunction with a novel rotating fluidized particle bed reactor.

Abstract: A catalyst for purifying an exhaust gas includes an upstream side catalyst and a downstream side catalyst. The upstream side catalyst is disposed on an upstream side with respect to an exhaust gas flow, and the downstream side catalyst is disposed on a downstream side with respect thereto. The upstream side catalyst includes a first loading layer, being composed of an alumina containing Ba and La at least, and a first noble metal, being held by the first loading layer and being at least one member selected from the group consisting of Pd, Pd and Rh and Pd and Pt. Alternatively, in addition to the aluminum, the first loading layer can be composed of Ce, a solid solution of Ce and Zr and a solid solution of Ce, Zr and Y in an amount as less as possible.

Abstract: An emission control system especially for light duty diesel engines has a first catalyst, 2, positioned upstream of a second catalyst, 3. The first catalyst converts NO to NO2 and the second catalyst oxidises HC, CO and VOF. The tendency of the second catalyst to collect soot particles is reduced by combustion of the soot particles by NO2 from the first catalyst.

Abstract: A lean NOx trap in an exhaust system of a spark ignition internal combustion engine having a three-way catalyst upstream of the lean NOx trap, and the lean NOx trap connected in series along the exhaust system is heated by modulating the air to fuel ratio (AFR) of the engine cyclically at various frequencies such as 0.5 Hz, 1 Hz, 1.5 Hz, and 2 Hz, so that different portions of the lean NOx trap are heated at different times so as to completely remove sulfur from the lean NOx trap.

Abstract: A stable, close-coupled catalyst, an article comprising the close-coupled catalyst and a related method of operation. The close-coupled catalyst comprises a catalyst support and a palladium catalytic component. Preferably and optionally, there are stabilizers including alkaline metal oxide, and rare earth metal components selected from the neodymium and lanthanum components. The close-coupled catalyst composition includes substantially no additional oxygen storage component such as praseodymium or cerium compounds. There is preferably a catalyst such as a three-way catalyst downstream of the close-coupled catalyst. The downstream catalyst preferably includes an oxygen storage component such as cerium oxide or praseodymium oxide.

Abstract: A catalyst for the purification of an exhaust gas emitting from a lean burn engine using gasoline as a fuel thereof and a method for the purification are provided. The catalyst has deposited on an inert carrier a mixture of a catalytically active component comprising palladium, an oxide of at least one alkali metal selected from the group consisting of potassium, sodium, rubidium, and cesium, and an oxide of at least one iron family metal selected from the group consisting of cobalt, nickel, and iron with a refractory inorganic oxide. This catalyst is used either alone or in combination with an oxidizing catalyst or a three-way catalyst for the purification of the exhaust gas from the lean burn engine using gasoline as a fuel thereof.

Abstract: An exhaust-gas-purifying catalyst is made by depositing on a support iridium serving as a catalyst active substance, sulfur for improving the catalyst activity of iridium and, if necessary, platinum. The sulfur is preferably contained as a sulfate. The exhaust-gas-purifying process of the present invention is a process in which exhaust gas from an internal combustion engine is allowed to pass through the exhaust-gas-purifying catalyst with the exhaust-gas temperature being set in the range of 200° C. to 700° C. at the inlet of the exhaust-gas-purifying catalyst. The above-mentioned composition and process provide an activity for purifying exhaust gas, especially for eliminating nitrogen oxides in an oxidizing atmosphere, in a wide temperature range, allow high heat-resistance and durability, and consequently, are superior in practical use.